From: Akinobu Mita <akinobu.mita@xxxxxxxxx> Subject: fault-inject: parse as natural 1-based value for fail-nth write interface The value written to fail-nth file is parsed as 0-based. Parsing as one-based is more natural to understand and it enables to cancel the previous setup by simply writing '0'. This change also converts task->fail_nth from signed to unsigned int. Link: http://lkml.kernel.org/r/1491490561-10485-3-git-send-email-akinobu.mita@xxxxxxxxx Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/fault-injection/fault-injection.txt | 7 +++---- fs/proc/base.c | 9 ++++----- include/linux/sched.h | 2 +- 3 files changed, 8 insertions(+), 10 deletions(-) diff -puN Documentation/fault-injection/fault-injection.txt~fault-inject-parse-as-natural-1-based-value-for-fail-nth-write-interface Documentation/fault-injection/fault-injection.txt --- a/Documentation/fault-injection/fault-injection.txt~fault-inject-parse-as-natural-1-based-value-for-fail-nth-write-interface +++ a/Documentation/fault-injection/fault-injection.txt @@ -138,8 +138,8 @@ o proc entries - /proc/self/task/<current-tid>/fail-nth: - Write to this file of integer N makes N-th call in the current task fail - (N is 0-based). Read from this file returns a single char 'Y' or 'N' + Write to this file of integer N makes N-th call in the task fail. + Read from this file returns a single char 'Y' or 'N' that says if the fault setup with a previous write to this file was injected or not, and disables the fault if it wasn't yet injected. Note that this file enables all types of faults (slab, futex, etc). @@ -320,7 +320,7 @@ int main() system("echo N > /sys/kernel/debug/failslab/ignore-gfp-wait"); sprintf(buf, "/proc/self/task/%ld/fail-nth", syscall(SYS_gettid)); fail_nth = open(buf, O_RDWR); - for (i = 0;; i++) { + for (i = 1;; i++) { sprintf(buf, "%d", i); write(fail_nth, buf, strlen(buf)); res = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds); @@ -339,7 +339,6 @@ int main() An example output: -0-th fault Y: res=-1/23 1-th fault Y: res=-1/23 2-th fault Y: res=-1/23 3-th fault Y: res=-1/12 diff -puN fs/proc/base.c~fault-inject-parse-as-natural-1-based-value-for-fail-nth-write-interface fs/proc/base.c --- a/fs/proc/base.c~fault-inject-parse-as-natural-1-based-value-for-fail-nth-write-interface +++ a/fs/proc/base.c @@ -1360,7 +1360,8 @@ static ssize_t proc_fail_nth_write(struc size_t count, loff_t *ppos) { struct task_struct *task; - int err, n; + int err; + unsigned int n; task = get_proc_task(file_inode(file)); if (!task) @@ -1368,12 +1369,10 @@ static ssize_t proc_fail_nth_write(struc put_task_struct(task); if (task != current) return -EPERM; - err = kstrtoint_from_user(buf, count, 0, &n); + err = kstrtouint_from_user(buf, count, 0, &n); if (err) return err; - if (n < 0 || n == INT_MAX) - return -EINVAL; - current->fail_nth = n + 1; + current->fail_nth = n; return count; } diff -puN include/linux/sched.h~fault-inject-parse-as-natural-1-based-value-for-fail-nth-write-interface include/linux/sched.h --- a/include/linux/sched.h~fault-inject-parse-as-natural-1-based-value-for-fail-nth-write-interface +++ a/include/linux/sched.h @@ -974,7 +974,7 @@ struct task_struct { #ifdef CONFIG_FAULT_INJECTION int make_it_fail; - int fail_nth; + unsigned int fail_nth; #endif /* * When (nr_dirtied >= nr_dirtied_pause), it's time to call _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
